Semiconductor devices may be fabricated by implanting ions into a workpiece disposed on a platen. Traditionally, ion implants were performed at room temperature. However, more recently, it has been found that certain ion implant techniques may be improved if the temperature at which the ion implant is performed is elevated. For example, in certain embodiments, the ion implant may be performed at a temperature in excess of 500° C.
However, one issue associated with ion implants at elevated temperatures is monitoring the temperature of the platen or workpiece during the ion implant process. Various measurement techniques have been used. For example, specialized workpieces with integrated temperature sensors can be disposed on the platen to measure actual temperature. However, this technique uses valuable system time, which increases the cost of ownership, only provides data regarding the test workpiece, and is not a real time measurement.
Other attempts to measure temperature include the use of infrared to attempt to create a thermal map of the workpiece while the workpiece is being processed. However, thermal imaging with infrared may be difficult to interpret. Interpretation is often performed by one with specialized experience. In a semiconductor fabrication environment, such a person may or may not be available. In any event, the time for interpretation adds time to the total fabrication process.
Therefore, it would be beneficial if there was a system and method of determining the temperature of a platen and workpiece, while that workpiece is being processed by an ion beam. Further, it would be advantageous if this system and method could be incorporated into existing systems with minimal changes and provide feedback about the platen and workpiece temperature during implant to the semiconductor fabrication system.